Environmental protection paper material structure used for food containers and manufacturing method thereof

ABSTRACT

An environmental protection paper material structure for food containers and its manufacturing method include a paper layer roll printed and coated with a first crosslinker coating in compliance with the laws and regulations of an adhesive for food packaging on both surfaces by a roll printing method, and a biodegradable material layer coated on the surface of the two first crosslinker coatings by a film coating method, and a second crosslinker coating and an anti-adhesive coating roll-printed and coated on upper and lower external layers. The anti-adhesive coating at the external layer effectively prevents the biodegradable material layer from being in a direct contact with the moisture in the air or becoming sticky due to a temperature rise before the environmental paper material is cut into different shapes of paper containers or rolled or stacked for storage, and the paper material can be used directly for hot pressing and shaping.

FIELD OF THE INVENTION

The present invention relates to an environmental protection paper material structure used for food containers and a manufacturing method thereof, and the invention can achieve the effect of reducing the manufacturing process, increasing the productivity, and preventing layers of paper materials from being adhered with each other when the paper is coiled, stacked and stored.

BACKGROUND OF THE INVENTION

In R.O.C. Pat. Application No. 094206557 entitled “Degradable paper board used for food containers” and filed by the inventor of the present invention includes one independent claim and two dependent claims, the independent claim recites that a paper board of an original roll of paper forms a biodegradable polylactic acid (PLA) thin film layer on a surface of the paper board by a film coating method for cutting the paper board into various different paper table wares. The two dependent claims respectively recite that the biodegradable thin film layer is a PET thin film layer, and the biodegradable thin film layer is a starch layer.

The structure of PLA thin film layer coated on the paper board is characterized in that the structure complies with the laws and regulations of food-level containers, and adopts an automatic and consistent operation for its production. However, there is still a drawback that the structure at its preliminary manufacturing stage is generally rolled into a cylindrical roll by a rolling frame for easy and convenient storage, transportation and cutting, but the finished goods are damped by the moisture in the air and affected by the temperature when the goods are stored temporarily, such that the PLA thin film layer coated on a single surface of the paper board absorbs the moisture in the air and situates in a slightly dissolved conditions due to the rise of temperature. As a result, an adhesion occurs between two paper boards of the rolled paper, which will take lots of effort to spread out the paper and affect the operation at a later stage.

Further, the aforementioned biodegradable thin film layer made of a PET material generally causes a large thickness of the coated thin film layer when the film coating method is employed for the production. After the biodegradable thin film layer is hardened and shaped, the thin film layer will have a lower ductility, and thus the paper will be become brittle and cracked during the cutting and shaping operations of the container box.

In view of the insufficient structural strength of the prior art, the inventor of the present invention continued to conduct extensive researches and experiments, and finally developed an environmental protection paper material structure and a manufacturing method thereof in accordance with the present invention that has the advantages of complying with the laws and regulations of packages and containers at a food container level, manufacturing finished goods by a standard manufacturing procedure and overcoming the adhesive issues of the rolled paper of the finished goods.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a manufacturing method of environmental protection paper material for food containers, and the method comprises the steps of: adopting a paper layer of an original paper roll as a substrate for a standard operating procedure; using a roller module to roll print and coat both sides of the paper layer by film coating method; sequentially pressing a highly adhesive first crosslinker coating and a biodegradable thin film layer onto the paper layer; roll printing and coating a second crosslinker coating and an anti-adhesive coating onto upper and lower biodegradable thin film layers; roll printing and coating by another roller module; baking and shaping by a baking device; and rolling finished goods into a roll for hot pressing the paper material into various environmental protection paper containers. The invention is characterized in that the finished goods can be produced directly from the raw material of paper without interrupting the operation to switch to different manufacturing flows, so as to achieve the effects of effectively shortening the manufacturing time, enhancing production efficiency, and lowering manufacturing and labor costs.

Another objective of the present invention is to provide an environmental protection paper material for food containers, comprising: a highly adhesive first crosslinker coating, a biodegradable thin film layer and two outermost layers of second crosslinker coating and anti-adhesive coating roll-printed and coated sequentially onto a lower surface of a paper layer by a roller module by means of a film coating method, so that both sides of the paper layer are attached with several layers of thin film, wherein the first crosslinker coating and the second crosslinker coating are biodegradable adhesive material, and the anti-adhesive coating is an AC agent, so that when the environmental protection paper material is rolled or stacked for future use, the outermost anti-adhesive coating between the paper materials serves as an isolating protective layer for the biodegradable thin film layers to prevent the biodegradable thin film layers from being in a direct contact with the moisture in the air or having an adhesive situation when the temperature rises. In addition, the present invention further provides another function to facilitate spreading the paper material flatly and directly cutting the paper into various different containers by the hot pressing and shaping process of the second crosslinker coating, and effectively overcome the shortcomings of the prior art structure that requires a second-time coating of the crosslinker coating and a complicated manufacturing procedure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of a preferred embodiment of the present invention; and

FIG. 2 is a section view of a paper material structure of a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 and 2 for a flow chart of a manufacturing method of an environmental protection paper material for food containers and a section view of an environmental protection paper material structure in accordance with a preferred embodiment of the present invention respectively, the manufacturing method comprises the following steps:

A paper layer 10 of an original paper roll is transmitted by a roller and roll-printed and coated with upper and lower first crosslinker coatings 21, 22 of an adhesive 20 for food packaging by a roller module, wherein the adhesive is made of a highly adhesive biodegradable material such as a FEPOL material or other materials with equivalent properties. Then, a first baking device 31 is used for shaping the upper and lower first crosslinker coatings 21, 22 on both sides, and a surface of the upper first crosslinker coating 21 is pressed and coated with a first biodegradable thin film layer 4 (situated at the top surface) for a first time by a film coating machine 41, and a cooling roller module 43 is used for pressing the upper first crosslinker coating 21 and the upper first biodegradable thin film layer 4 as a whole, and then a surface of the lower first crosslinker coating 22 is pressed and coated with a second biodegradable thin film layer 52 (situated at the bottom surface) for a second time by another film coating machine 51, and another cooling roller module 53 similarly presses and shapes the lower first crosslinker coating 22 and the second biodegradable thin film layer 52, and a second crosslinker coating 23 and an anti-adhesive coating 24 are rolled printed and coated on both surfaces for the protection operation by another roller module, wherein the anti-adhesive coating 24 is an adhesive 20 made of an AC agent, such that after the second baking device 32 finishes baking and shaping, a finished good 60 is rolled into a paper rolling stand for the future use of making various types of environmental protection paper containers or paper cover, so as to achieve the standard manufacturing procedure, enhance the mass production, and lower the manufacturing cost effectively.

The aforementioned original roll of paper layers has gone through preheating and corona treatment), and then the upper and lower first crosslinker coatings 21, 22 are roll-printed and coated to provide a better effect of the crosslinker coating to be adhered quickly onto a surface of the paper layer. Further, the corona treatment can be performed to the second crosslinker coating 23 and the anti-adhesive coating 24 before the roll printing and coating processes to improve the adhesive effect of the crosslinker coating 23 and the anti-adhesive coating 24.

The degradable material of the upper and lower first crosslinker coatings 21, 22 and the second crosslinker coating 23 used by the aforementioned adhesive 20 for food packaging are a FEPOL material in compliance with food level safety package standard and having high strength, melting point, stability, shock resistance, ductility and manufacturability. After a thin film is formed, excellent pull resistance and firmness can be achieved, and these features can prevent the second crosslinker coating at the outermost surface from becoming brittle and cracked by bending and extending the environmental protection paper during the hot pressing and shaping process of the table wares or containers. In addition, the FEPOL is used as an environmental protection paper material with a second crosslinker coating, and the FEPOL thin films are attached with the edges of each other to overcome the shortcomings of the prior art that requires a second-time coating of adhesives. The foregoing adhesive can be made of a material such as the Dupont's 52009 APPEIL or any other material with equivalent properties.

Similarly, the anti-adhesive coating is made of a material in compliance with the laws and regulations of an adhesive for food packaging, and the adhesive is an anchor coating (AC) agent, and the AC agent one selected from the collection of a biodegradable titanium series, a ployamine series, a polyethylene imide series and a polybutadiene series. The second crosslinker coating adopting the AC agent serves as an isolating layer for preventing the paper materials from being adhered with each other when the paper material is stacked flatly or rolled into a roll.

It is noteworthy to point out that the FEPOL a material developed by an ester polymerization technology and applied in microbiology as a highly degradable polymer material, such that when the FEPOL is used at a fertilization operating stage, it is converted completely into carbon dioxide and water, which is definitely unlike the aforementioned series of AC agents. The roll-printing and coating of the roller module can press a crosslinker coating with a thickness smaller than that pressed by a film coating machine, such that after the crosslinker coating is hardened and shaped, the ductility is improved to effectively prevent the paper material from becoming brittle and cracked easily.

The biodegradable thin film layers 42, 52 of the invention are made of biodegradable materials, bio-polymers or green plastics, in compliance with the standards of fertilization as specified by the IS014855 certification, and are thermoplastic materials that are not affected by environmental pollutions. The biodegradable thin film layers 42, 52 are made of polylactic acid (PLA), polythylene terephthalate (PET) or any other biodegradable material similar to PET such as Dupont's Biomax 4024 PET, special LDPE, or Taiwan Far East Textile's degradable FEPOL particles.

Referring to FIG. 2 for a structure of an environmental protection paper material with a multiple layers of composite thin films for food containers in accordance with the present invention, a paper layer 10 is used as a substrate, and an upper first crosslinker coating 21, a first biodegradable thin film layer 42 and an upper second crosslinker coating 23 are pressed sequentially onto an upper surface of the paper layer 10, and a lower first crosslinker coating 22, a second biodegradable thin film layer 52 and a lower second crosslinker coating 24 are pressed sequentially onto a lower surface of the paper layer 10, wherein each crosslinker coating 21, 22, 23 is a highly adhesive FEPOL material, Dupont's 52009 APPEIL, or any other material with equivalent properties in compliance with the laws and regulations of an adhesive for food packaging, and the crosslinker coating 24 is an anchor coating (AC) agent in compliance with the laws and regulations of an adhesive for food packaging, and the AC agent is one selected from the collection of a biodegradable titanium series, a ployamine series, a polyethylene imide series and a polybutadiene series for improving the adhesion between the paper layer 10 and the biodegradable thin film layer 42, 52. In addition, the lower second crosslinker coating 24 disposed at the outermost surface serves as an isolating protective layer for the biodegradable thin film layer 42, 52, such that after the paper material is cut into a predetermined shape, the paper material can be applied for a hot pressing and shaping operation directly, so as to waive the inconvenient second-time manufacturing step of coating the adhesive before performing the hot pressing and shaping process.

In summation of the above description, the present invention enhances the performance than the conventional structure and further complies with the patent application requirements and is duly filed for patent application.

While the invention is described in some detail with reference to certain illustrated embodiments, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures. 

What is claimed is:
 1. A method of manufacturing an environmental protection paper material for food containers, comprising the steps of: performing upper and lower first crosslinker coatings on both sides of a paper layer of an original paper roll by roller printing of a roller module; shaping the upper and lower first crosslinker coatings by a first baking device; pressing and coating a first biodegradable thin film layer onto a surface of the upper first crosslinker coating by a film coating machine, and compressing the first biodegradable thin film layer and the upper first crosslinker coating into a whole; pressing and coating a second biodegradable thin film layer onto a surface of the lower first crosslinker coating by another film coating machine, and compressing and shaping the second biodegradable thin film layer and the lower first crosslinker coating by another cooling roller module; and roll printing and coating a second crosslinker coating and an anti-adhesive coating on external surfaces of the first and second biodegradable thin film layers respectively by another roller module, and performing baking and shaping processes by a second baking device, and rolling, shaping and rolling finished goods into a roller stand.
 2. The method of manufacturing an environmental protection paper material for food containers as recited in claim 1, wherein the crosslinker coating is a material in compliance with the laws and regulations of an adhesive for food packaging.
 3. The method of manufacturing an environmental protection paper material for food containers as recited in claim 1 or 2, wherein the upper and lower first crosslinker coatings and the second crosslinker coating are a FEPOL material or Dupont's 52009 APPEIL or any other material with the same properties.
 4. The method of manufacturing an environmental protection paper material for food containers as recited in claim 1, wherein the anti-adhesive coating is an anchor coating (AC) agent.
 5. The method of manufacturing an environmental protection paper material for food containers as recited in claim 4, wherein the anti-adhesive coating is one selected from the collection of a biodegradable titanium series, a ployamine series, a polyethylene imide series and a polybutadiene series.
 6. The method of manufacturing an environmental protection paper material for food containers as recited in claim 1 or 2, wherein the crosslinker coating is an ester material that can be converted completely into carbon dioxide and water at a fertilization operating stage.
 7. An environmental paper material structure for food containers, comprising: an upper first crosslinker coating, a first biodegradable thin film layer and a second crosslinker coating, pressed sequentially onto an upper surface of a paper layer, and a lower first crosslinker coating, a second biodegradable thin film layer and an anti-adhesive coating, pressed sequentially onto a lower surface of the paper layer.
 8. The environmental paper material structure for food containers as recited in claim 7, wherein the crosslinker coating is a material in compliance with the laws and regulations of an adhesive for food packaging.
 9. The environmental paper material structure for food containers as recited in claim 7 or 8, wherein the upper and lower first crosslinker coatings and the second crosslinker coating are a FEPOL material or Dupont's 52009 APPEIL or any other material with the same properties.
 10. The environmental paper material structure for food containers as recited in claim 7, wherein anti-adhesive coating is an anchor coating (AC) agent.
 11. The environmental paper material structure for food containers as recited in claim 10, wherein the anti-adhesive coating is one selected from the collection of a biodegradable titanium series, a ployamine series, a polyethylene imide series and a polybutadiene series.
 12. The environmental paper material structure for food containers as recited in claim 7 or 8, wherein the crosslinker coating is an ester material that can be converted completely into carbon dioxide and water at a fertilization operating stage. 